(INDIANAPOLIS) - A warehouse fire that began just before 1 p.m. Saturday was brought under control after nearly eight hours, though hot spots could continue to smolder for several days, fire investigators said.

The fire broke out at 220 Belmont Ave. in a building that formerly housed a Link Belt facility. The 440,000-square-foot building was being leased by Shelter Distribution, Mercury Trucking, Zen Trucking, Nationwide OTR and two general contractors. Former workers said it is at least 90 years old.

Investigators said late Saturday that about 60 percent of the building that houses six businesses had collapsed. The fire also burned the Belmont Warehousing building across the street.

Evacuations of a five-block area around the fire were lifted early Sunday morning. Officials were concerned about toxins from the heavy, black smoke wafting through the air.

Indianapolis police said that up to 100 homes were evacuated bounded by Harding Street and Belmont Avenue from east to west and from Oliver Avenue to Washington Street south to north.

Officers drove down the streets, using a loudspeaker to detail the evacuation. They then went door-to-door to follow up.

The fire was in a warehouse that contains 65,000 square feet of wooden pallets, siding and heavy equipment, along with 85,000 square feet of tires, officials said.

Explosions rocked the building several times as the fire raged, and it will take quite some time to douse all the hotspots, Indianapolis fire Capt. Rita Burris said. About 30 propane tanks exploded during the fire.

No one was inside the buildings that burned, but four firefighters suffered minor injured while battling the fire, Burris said. About 200 emergency personnel, including firefighters from seven departments, were involved in the fight.

A few nearby residents who complained of smoke inhalation were checked out at the scene. None were taken to hospitals.

Fire officials had been concerned that the blaze could spread because burning embers had been lifted into the air, scattering smoldering debris. There were several small Dumpster and nearby building fires started by burning debris.

Air quality experts from the Environmental Protection Agency, the Centers for Disease Control and Prevention and the Marion County Health Department were monitoring the situation.

People who live downwind of the fire outside the evacuation zone were urged to keep their windows closed. Smoke from the blaze could be smelled as far away as Fishers.

A shelter was set up at 441 E. 10th St., but most of the evacuees chose to stay with family members.

It was not immediately known what sparked the blaze. Investigators don't expect to be able to get into the rubble until Monday, at the earliest.